Shielding effectiveness of composite aircraft: A reverberation chamber and virtual measurement study

The current design trend away from aluminum skinned aircraft and toward composite materials has the potential to leave new aircraft vulnerable to electromagnetic interference. While traditional aluminum skin provides significant shielding to the electronics inside the aircraft, however, carbon-fiber composite aircraft provide substantially less shielding. This suggests the growing importance of characterizing, measuring and predicting the shielding effectiveness provided by the composite skin of an aircraft. The current practice of characterizing the shielding effectiveness of a fuselage in the prototyping phase leaves manufactures vulnerable to costly shielding mitigation and redesign work. This paper proposes a virtual measurement to help predict the shielding effectiveness during the design phase when changes are simpler and more cost effective. To demonstrate the rigor of the proposed virtual measurement method, the shielding effectiveness of a carbon-fiber composite uncrewed aircraft was measured in an industrial reverberation chamber. These qualified shielding effectiveness measurements then serve as a benchmark with which to compare the virtual measurement results. In making this comparison some interesting results between reverberation chamber and direct illumination shielding effectiveness came to light. This paper presents the virtual measurement method, the model validation work and early shielding effectiveness measurement comparisons.